Limits on Use of Foreign Prosecution History

Canmar Foods Ltd v TA Foods Ltd 2021 FCA 7 de Montigny JA: Pelletier JA, Rivoalen JJA affg 2019 FC 1233 Manson J

            2,582,376 / method for roasting oil seed

Yesterday’s post the summary judgment aspects of the Canmar appeal; this post turns to the issue of s 53.1, which permits the use of prosecution history to aid in claim construction in certain circumstances. Justice Manson’s decision at first instance was the first to interpret s 53.1, and a difficult issue was raised right off the bat. The defendant, TA Foods, wanted to refer to the US prosecution history, while s 53.1 on its face only permits use of communications between the patentee and “an officer or employee of the Patent Office”—which is to say, the Canadian prosecution history. As discussed here, Manson J held that foreign prosecution history should be admissible to aid in a construction of Canadian claims only in “extraordinary circumstances” [73], [74], [77]. In general, this means that “prosecution of the foreign application is made part of the prosecution history of the Canadian patent” [77, original emphasis]. While Manson J did consider the foreign prosecution history [85]–[90], he expressly stated that he would have come to the same conclusion in any event [79].

Justice de Montigny ultimately held that Manson J should not have referred to the foreign prosecution history on the facts in this case [77]. The FCA’s restrictive approach to the use of foreign prosecution history reflects the text of s 53.1, but at this point we cannot rule out the possibility that foreign prosecution history might be admissible if made part of the Canadian prosecution history with sufficient particularity. That is a question “left for another day” [74], and de Montigny JA emphasized that “I wish to express no firm views on the matter” [77].

More generally, de Montigny JA’s decision for the FCA provides a useful discussion of a number of issues, but ultimately refrained from deciding most of them, on the view that “courts [should] refrain from deciding beyond what is strictly necessary for the resolution of the case of which they are seized” [74]. In my view this is a salutary principle—I often wish the SCC would pay more heed to it. The result is that the decision illuminates the FCA’s thinking on this issue, while leaving the specifics to be developed in future cases that raise them more directly. This is the way the law should develop.

Value of foreign jurisprudence

Justice de Montigny noted that s 53.1 appeared to respond in part to disquiet expressed in some FC decisions about always excluding consideration of prosecution history, especially in some particularly egregious cases [51]–[53], and he also noted that “it can also be perceived as a step to better align Canadian law with its British and American counterparts” [53]. That is true in broad strokes—as de Montigny JA noted, US law of course has a well-developed doctrine of prosecution history estoppel [54]–[56], and even the UK has made some steps in that direction [57]–[62]. With that said, I do not see this as an invitation to draw detailed guidance from US or UK law (which are very different from each other), as de Montigny JA noted that s 53.1 “is carefully tailored, and it would go against statutory interpretation principles to try to go beyond its original intent” [70]. Our law relating to prosecution history will therefore turn on the interpretation s 53.1.

Need there be a specific representation?

Part of that careful tailoring is that prosecution history may be admitted “to rebut any representation” made by the patentee in the action. Justice de Montigny noted that a question has arisen as to whether there must be some specific representation as to the construction of the claim [65], or whether the emphasis “is not so much on the rebuttal of a particular representation, but rather on the interpretive process itself,” as suggested in Bauer Hockey 2020 FC 624 (discussed here): [66]. Justice de Montigny left this question for another day, as it was not necessary to decide the case at hand [67]. My impression is that he was leaning to the latter interpretation, but I can’t point to anything specific in the reasons to support that view, and in any event he expressly left the matter open.

Foreign prosecution history

The main issue raised on the facts was the use of foreign prosecution history. Justice de Montigny emphasized the need to adhere to the text of the provision [70], which suggests a very limited role, if any, for foreign prosecution history. Further, he noted that “There are also public policy reasons for treading carefully in allowing extrinsic evidence” [70]. Allowing foreign patent prosecution history into the analysis “might lead to overly contentious and expensive litigation,” given different law, differences in language potentially requiring translation, and differences in the registration system. He noted that “in this case, the patent application in the United States was eventually dropped, while registration in Canada was completed” [71]. Thus both textual and purposive considerations support a restrictive approach to the use of foreign prosecution history. At the same time he acknowledged the force of the argument for “keeping those who have previously disclaimed elements from their patent from re-claiming them in future infringement cases,” both in general [72] and on the facts of this case [73].

In this case, Manson J held that foreign prosecution history would be admissible in “extraordinary circumstances” [FC 73, 74, 77]. As noted above, Manson J described such circumstances as being where “that prosecution of the foreign application is made part of the prosecution history of the Canadian patent” [FC 77, original emphasis]; Canmar referred to this as an “incorporation by reference” theory [69]. On the facts of the case, “the patentee specifically referred to the corresponding US Application prosecution history and acknowledged that the amendments to the claims in the ‘376 file history were made to overcome novelty and obviousness concerns as raised in the US Application prosecution history” [FC 70], [68].

Justice de Montigny did not dismiss the possibility that some form of incorporation by reference doctrine might permit foreign prosecution history to be used under s 53.1, but he left this question “for another day,” as he was of the view that the facts at hand “do not lend themselves to a proper finding of incorporation by reference” [74]. Justice de Montigny noted that “There is nothing in the prosecution file of the ‘376 Patent that identifies with any detailed particularity what specific ‘written communication’ from the US prosecution history is incorporated and where that written communication can be found” [75]. The only mention is a response to the Examiner stating that the new claims correspond to those submitted during prosecution “of a related United States application” [75], and he remarked that “It is a stretch to say that the prosecution of the US Application is incorporated by reference when the specific application is not even cited within the document” [76]. There is some suggestion in the decision that US doctrine of incorporation by reference might provide some guidance [76], though it remains to be seen how influential this will be, as the matter will ultimately turn on the interpretation of s 53.1.

The FCA decision in Canmar therefore establishes that the foreign prosecution history cannot be used unless the Canadian prosecution history contains some fairly specific reference to the foreign prosecution history. It should be emphasized, however, that the converse is not necessarily true: this does not mean that the foreign prosecution history will be considered if there is a sufficiently specific reference in the Canadian file. Whether foreign prosecution history will be admissible at all, and if so, exactly what kind of reference is needed, is a question left for another day [74[.

In my view the FCA was entirely right to confine itself to the holding necessary to dispose of the appeal, while leaving other questions for another day. Section 53.1 is novel—it does not appear to reflect any particular foreign jurisprudence—and it is detailed. Accordingly it will be best for the law to develop incrementally, at least for a period as we get a better understanding of the issues that will be raised by s 53.1 in different factual contexts.